japonica vs Chaenomeles japonica

japonica and Chaenomeles japonica both are nouns.

Word	Noun	Adjective	Verb	Adverb
japonica	Yes	No	No	No
Chaenomeles japonica	Yes	No	No	No

As nouns, japonica and Chaenomeles japonica are synonyms defined as:

japonica and Chaenomeles japonica: deciduous thorny shrub native to Japan having red blossoms

Other synonyms of japonica include maule's quince.

japonica (noun)	Chaenomeles japonica (noun)
deciduous thorny shrub native to Japan having red blossoms	deciduous thorny shrub native to Japan having red blossoms
greenhouse shrub with glossy green leaves and showy fragrant rose-like flowers; cultivated in many varieties